Firearm with adjustable lock-up time device



Nov. 5, 1968 G. A. LOPEZ 3,408,895

FIREARM WITH ADJUSTABLE LOCK-UF TIME DEVICE Filed Jan. 5, 1967 2 Sheets-Sheet 1 iff I /3 38 /2 l,

d Ii-EM a I TB 67 WM 73 f 22 INVENTOR. GM afer ,4. ope-Z,

Nov. 5, 1968 G. A. LoPf-:z 3,408,895

FIREARM WITH ADJUSTABLE LOCK'UP TIME DEVICE Filed Jan. 5, 1967 2 Sheets-Sheet 2 BY 55 QW/mf www United States Patent 3,408,895 FIREARM WITH ADJUSTABLE LOCK-UP y TME DEVICE Gilbert A. Lopez, Fort McKavett, Tex. 76841 Filed Jan. 3, 1967, Ser. No. 606,685 6 Claims. (Cl. 89-145) vABSTRACT F THE DISCLOSURE This invention relates to firearms, and more particularly, to an adjustable means for disengaging the sliding breech block or bolt from the barrel extension of an automatic firearm responsive to recoil after firing, the adjustment being for the purpose of compensating for different types of ammunition employed in the firearm without the necessity of having to disassemble the firearm or physically altering or substituting any of its parts.

A main object of the invention is to provide an improved readily adjustable means for setting the release time at which the breech block or sliding bolt of an automatic or semi-automatic firearm disengages from the 4barrel extension portion thereof responsive to recoil after firing, in accordance with the power of the ammunition employed in the firearm and so as to provide optimum utilization of the ammunition in operating the mechanism of the firearm, whereby satisfactory operation may be obtained over a wide range of types of ammunition employed.

A further object of the invention is to provide an improved lock-up time-adjusting means for adjusting the time of release of the sliding breech block or bolt of an automatic or semi-automatic firearm from the barrel extension thereof responsive to recoil after firing so as to compensate for different types of ammunition which may be employed in the firearm, the device being simple in construction, involving inexpensive parts, being reliable in operation, and being easy to adjust without requiring the necessity of complicated tools.

A still further object of the invention is to provide an improved means for adjusting the time of disengagement of the sliding breech block or bolt of an automatic or semiautomatic firearm from the barrel extension thereof, responsive to recoil after firing, so that low-power ammunition as well as high-power ammunition can be fired in the same firearm by making a simple adjustment and without having to disassemble the firearm or physically alter or substitute for any of its parts, the device being applicable to firearms which operate on the recoil principle or to thoseoperating on other principles, such as on the gasoperating principle, the device providing a wide range of adjustments to take care of corresponding different types of ammunition so that low-power ammunition as well as high-power ammunition can be fired in the same firearm 'by making the proper adjustment, and so that the mechanism of the firearm will operate properly and will be efiiciently coordinated with the specific type of ammunition employed.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

FIGURE l is a fragmentary longitudinal vertical crosssectional view taken through the rear portion of a firearm provided with an improved lock-up time-adjusting device constructed in accordance with the present invention.

FIGURE 2 is a horizontal cross-sectional view taken substantially on the line 2-2 of FIGURE 1.

FIGURE 3 is a longitudinal vertical cross-sectional view taken substantially on the line 3-3 of FIGURE 2.

FIGURE 4 is a fragmentary longitudinal vertical crosssectional view similar to FIGURE 1, but showing the firearm with the parts thereof in positions assumed shortly after firing, namely, during the first portion of the recoil period at the point where the breech block or sliding bolt becomes mechanically disconnected from the barrel extension of the firearm.

FIGURE 5 is a fragmentary longitudinal vertical crosssectional view, similar to FIGURES 1 and 4, but showing the positions of the parts substantially at the end of the recoil action, with the sliding breech block or bolt released from the barrel extension.

FIGURE 6 is a fragmentary enlarged perspective view of the rear portion of the barrel extension, the sliding breech block or bolt, the lock member for connecting the bolt to the barrel extension, and other parts associated with these elements, the parts being shown in separated positions.

FIGURE 7 is a fragmentary side elevational view showing a modification of an adjustable lock-disengaging mechanism for a firearm in accordance with the present invention.

In automatic firearms or semi-automatic firearms which are of the lock-up type, namely, of the type wherein the breech and breech block, bolt or slide are mechanically held locked together at the time of firing and remain so until mechanically unlocked and permitted to separate at some time during the firing cycle, the power of the ammunition employed has been a critical factor for satisfactory operation. Ammunition containing too low a charge would fail to operate the mechanisms properly, and ammunition containing too high a charge would cause the mechanisms to operate with excessive violence. This has been true with firearms operating on the recoil principle, as well as on the gas-operating principle. Thus, satisfactory operation depends heavily upon the use of a proper charge (propellant or power) of ammunition, coordinated with the lock-up time of the firearm. Lockup time is defined herein as the time lag from the instant of firing until the breech and sliding breech block, bolt or slide, become unlocked or mechanically separated. A prime purpose of the present invention is to provide a mechanism including means to adjust the lock-up time so that low-power ammunition as well as high-power ammunition can be fired in the same firearm by making a simple adjustment and without having to disassemble the firearm or to physically alter or substitute for any of its parts.

Referring to the drawings, and more particularly to FIGURES 1 to 6, 11 generally designates a firearm of the type employing a recoil-operated barrel element 12 and a sliding breech block or bolt 13. The firearm 11 is provided with the frame 14 integrally-formed with the hollow handle portion 15 which defines a magazine for the cartridges employed by the firearm and which are supplied automatically to the breech portion of the firearm in a conventional manner as the firearm is operated. The frame 14 slidably-receives the barrel 12 in a bore 16 provided for the barrel, the sliding movement of the barrel being limited by a stop pin 17 fixedly-secured to the frame and projecting into a longitudinal groove 18 provided in the barrel. The sliding bolt 13 is formed with a longitudinal bore 19 which slidably-receives a guide pin 20 longitudinally-mounted in the upper rear portion of the rectangular main recess 21 of frame 14, a coiled spring 22 surrounding the pin 20 and bearing between the slidin-g bolt 13 and an enlarged rear head portion 23 provided on pin 20, as clearly shown in FIGURE 1. The barrel 12 is provided with the rearward flat extension 25 which is slidably-received in the main recess 21 and which is formed with a longitudinal bore 26 slidably-receiving the shank of a headed guide pin 27, a coiled spring 28- being provided on the shank of pin 27 bearing between the head thereof and the adjacent Vertical end edge of the extension 25. The springs 22 and 28 act to bias barrel 12 and breech block or bolt 13 forwardly toward normal positions thereof, such as those shown in FIGURE I. As will be presently explained, thecoiled spring 22 acts as a recoil cushioning means and becomes compressed by the rearward movement of the lbreech block 13, for example, to the position thereof shown in FIGURE 5, responsive to firing the weapon.

As will be apparent from FIGURE 6, the forward portionr of the breechv'block 13 is thickened to define an abutment shoulder 30, the bore 19 opening at said shoulder and the spring 22 bearing thereagainst.

The breech block 13 extends slidably through a rectangular aperture 31 formed in the rear end portion of frame 14, the rear end portion of breech block 13 being provided with a removable cap 33. The rear end portion of breech block 13 is formed with opposite vertical grooves 34, 34 and the cap 33 has a rectangular cavity 35 with opposing inturned vertical edge portions 36, 36 engageable in the grooves 34, 34, so that the cap member 33 receives the rectangular head 37 defined by the opposed vertical grooves 34, 34. The cap member 33 is provided with the knurled opposite end surfaces 38, 38 which are exposed at the opposite sides of the rear portion of the firearm, whereby to be readily gripped when it is desired to pull the breech block rearwardly, whereby to provide access to the breech portion of the firearm. The cap member 33 can be disconnected from the breech block 13, when desired, by disengaging the edges 36, 36 from the grooves 34, 34, namely, by pulling the cap member upwardly with the breech block partly retracted.

Frame 14 is apertured at opposite sides at the rear end thereof, as shown at 39 and 40, to receive the opposite end portions of cap member 33 with the knurled surfaces 38 substantially ush with the adjacent side surfaces of` frame 14, as shown in FIGURE 2.

The firearm 11 is provided with the rotatable hammer 42 which is rigidly-connected to a sear cam 43 biased in a counterclockwise direction, as viewed in FIGURE 1, by a forwardly-biased sear plunger 44 connected to cam 43 by a link arm 45. The hammer 42 is rotatable, under the biasing force of the driving plunger 44, into a recess 46 provided in the underside of the sliding breech bolt 13, whereby the hammer may strike the head of a firing pin 47 slidably-mounted in a conventional manner in a bore 48 longitudinally-formed in the bolt 13. The cam 43 may be, at times, held in a rotated position with the hammer 42 retracted, namely, in cocked position, by the engagement of a sear arm 49 with a detent shoulder 50 provided on the cam 43. The sear arm 49 has a depending arm 51 having a latera-lly-projecting release lug 51' which is engageable by the rearwardly-extending, downwardly-offset disconnection arm 52 of a disconnector lever 53 pivoted at 54 to the trigger 55 of the firearm. The top end portion of trigger 55 is pivoted at 56 to frame 14 and the trigger is biased forwardly by the action of a biasing spring 57 bearing between an abutment element 58 rigid with frame 14 and the u-pstanding end lug 59 provided on disconnector lever 53, as shown in FIGURE 1. When trigger 55 is rotated in a counterclockwise direction, as viewed in FIG- URE 1, the arm 52 acts against the lug element 51 to rotate the sear member 49 in a counterclockwise direction, for example, from the position of FIGURE 5, thereby releasing the cam 43 and allowing the hammer 42 to rotate counterclockwise and to strike the head of the tiring pin 47, to thereby fire the weapon.

The weapon is provided with a resilient trigger guard 61 having its upper end portion pivoted at 62 to frame 14 and having its lower end portion lockingly-engaged in a detent notch 64 provided in the upper portion of the front wall of handle 15, as shown in FIGURE 1. The top end 65 of the trigger guard 61 underlies the .locking pin 17, normally preventing said pinr17 from descending, and thereby maintaining the top endl portion of pin 17 in the retaining recess 18 of barrel 12. When the rear end of trigger guard 61 is disengaged from notch 64 and the trigger guard is rotated in 'a clockwise direction from the position thereof shown in FIGURE 1, the cam-like top end portion 65 of the trigger guard rotates sufficiently to provide clearance below pin 17 sufficient to allow the pin 17 to descend and disengage from groove 18, whereby to allow the barrel 12 and lthe bolt 13 to be removed from frame 14. v v I The sidewall of bolt member 13 is Aformed at its forward end portion with a recess 66 which receives a locking arm 67, the locking arm being arranged vertically in the recess 66 and being pivoted thereto at its rear end portion, namely, near the rear end of recess 66 by a transverse pivot pin 68. The locking arm 67 is provided with the forwardlyflared body having a depending forward'end lug portion 69 and being provided with a laterally-projecting pin element 70 at its upper forward corner. Pin element 70 is received in a longitudinally-extending slot 71 provided in the flattened rearward-ly-extending vertical arm portion 25 of barrel 12. Slot 71y is formed with a depending vertical front portion 72 in which pin 70 is likewise receivable and in the lower end of which pin 70 is positioned in the normal condition of the firearm shown in FIGURES 1, 2 and 3. Locking arm 67 is biased in a counterclockwise direction, as viewed in FIGURE l, by a forwardly-urged plunger element 73 slidable in a groove-like longitudinal extension 74 of recess 66 and being biased forwardly by a coiled spring 75 mounted in recess 74. The plunger element 73 acts on an upwardly-projecting lug 76 formed on the rear end portion of arm 67 adjacent the pivotal connection provided by pin 68.

It will thus be seen that the spring 75 acts on the locking arm -67 to bias said arm in a counterclockwise direction, as viewed in FIGURE l, namely, to a position wherein the pin 70 is in the lower portion of the forward, vertical, slot section 72.

Threadedly-engaged in the rear end portion of frame 14 is an adjustable, longitudinally-extending release rod 78 having a tapered tip 79 disposed in the path of rearward movement of lug 69, and being engaged by said lug when the breech block 13 is moved rearwardly with barrel 12 responsive to the firing of the weapon, namely, by the weapon recoil. It will be seen that the pin 70 maintains the breech block or bolt member 13 locked with the barrel member 12 as long as pin 70 is in the vertical slot portion 72. As lug 69 is engaged by the tip 79, the locking member 67 is rotated in a clockwise direction, as Viewed in FIGURE 1, whereby pin 70 rises so that it becomes aligned with the longitudinal portion of the slot 71, thereafter allowing the breech block 13 to move rearwardly independently of barrel member 12. By adjusting the longitudinally-extending rod element 78, the moment of disconnection of the breech block 13 from the barrel 12 after firing, can be regulated in accordance with the type of ammunition employed. Thus, the threaded bore containing the rod 78 opens at the rear end of frame 14 providing access to the slotted rear end of rod 78 by a screwdriver or similar implement. The sidewall of the frame 14 is provided with a viewing aperture, partly shown at 80, affording a view of calibration numbers 81 inscribed on the rod 78, providing a means of determining the degree of adjustment of the release rod 78, the num-j bers on the adjustment scale corresponding to various types of ammunition which may be employed with the Weapon, so that the rod 78 may be set accurately to the proper position thereof corresponding to a selected type of ammunition.

As is well understood by those familiar with this art, at the time of firing of the weapon, the recoil or rearward thrust of the powder (propellant) gases forces the barrel 12 with its extension 25, and the bolt 13, locked together by pin element 70, rearwardly. The members 12 and 13 remain locked together until the lug 69 is engaged by the tip 79 of rod 78, forcing the locking member 67 upwardly and unlocking the bolt 13 from the barrel extension 25, thereby allowing the bolt and barrel to separate, as shown in FIGURE 4. As the recoil action forces the barrel 12 and the barrel extension 25 rearwardly, the barrel extension spring 28 is compressed. At the same time, the bolt 13 is forced rearwardly and compresses the recoil spring 22. As the bolt 13 is forced rearwardly, it forces the hammer 42 rearwardly into the cocked position thereof shown in FIGURE 5. The disconnector arm 52 is moved to an elevated position, as shown in FIGURE 5, unable at this time to act upon the release lug 51 of sear member 49, although the sear member is lockingly-engaged with the cam shoulder 50.

As will be apparent, the weapon cannot be fired with the bolt 13 in its rearwardly-moved position shown in FIGURE 5. Firing ca n only occur when the weapon is in its normal position, as shown in FIGURE l, wherein the depending lug 69 overlies the bent portion 84 of the disconnector member 53, since this holds the disconnector member down sufficiently to align the arm 52 with the lug 51. When the lock member 67 moves rearwardly with the bolt 13, the lug 69 is no longer in a position to bear on the bent portion 84 of disconnector member 53 so that the disconnector arm 52 is, therefore, not in proper alignment to act on the sear lug 51.

At the time of unlocking, determined by the adjusted position of the rod member 78, the barrel extension spring 28 acts on the barrel extension 25 and begins to urge it forwardly, namely, ybegins to act to return the barrel to its normal position shown in FIGURE l,

namely, the position occupied thereby at the time ofA firing. When the bolt member 13 has reached its maximum rearward travel, such as that shown in FIGURE 5, the .recoil spring 22 returns it forwardly against the barrel breech, namely, to the position of FIGURE l. As the bolt 13 contacts the barrel at the breech portion 90 thereof, the laterally-projecting pin element 70 on the lock member 67 is forced downwardly by plunger element 73 into the bottom portion of the vertical slot segment 72, thus locking the bolt 13 to the barrel extension 25 and at the same time, moving arm 52 into alignment with sear lug 51. The forward motion of the bolt 13 acts in a conventional manner to strip a cartridge from the magazine and to push it into the barrel 12, ready for subsequent firing. Extraction and ejection of spent cartridges are performed by conventional means responsive to the rearward movement of the bolt 13 produced by recoil action.

The lock-up time-adjusting member 78 can be adjusted forwardly (closer to the breech) for faster unlocking, as when using weaker-powered ammunition, or rearwardly (further from the breech) for slower unlocking, as when using more powerful ammunition. This adjustment is performed by merely rotating the rod element 78 by means of a screwdriver or similar implement engaged through the tool-access space provided at the rear end of the internally-threaded `bore 93 provided for the rod member 78.

While the specific embodiment disclosed in FIGURES 1 to 6 shows a threaded adjusting rod element 78,A any other suitable means, other than threads, may be employed for adjusting the position of the contact tip 79 or equivalent contacting element. Thus, any suitable construction may be utilized for timing the movement of the locking member 67, or other equivalent locking member which may be employed, so as to suitably adjust the time period in which the firearm remains with a closed breech, or locked breech, during the operating or firing cycle. This time period is the time required for the parts to travel to a position at which the unlocking or unbreeching of the firearm is accomplished.

Where more strength in the lock-up is required than can be provided by the use of only a single locking member 67, the firearm may be designed with two barrel extensions 25, one on each side of the bolt, and the cartridge ejection can be arranged through the top of the frame 14 or laterally thereof -below either barrel extension. This permits the use of two locking members 67, one on each side of the bolt.

It should also be understood that the barrel extension 25 may have any desirable position, and is not necessarily limited to the specific location thereof illustrated in FIGURE 6. Also, as above-stated, more than one barrel extension may be employed if desired.

As above-mentioned, a viewing window is provided through which the markings 81 on the rod member 78 may be observed. As above-mentioned, the markings serve as reference data to establish the proper lock-up time for particular loads, or ammunition types.

FIGURE 7 illustrates a modified arrangement wherein the trigger 55 and disconnector member, shown at 53', are biased forwardly by a tension spring 57' connecting the end of the member 53' to a fixed portion 95 of the frame shown at 14'. The disconnector member 53 is thus biased toward the full-line position thereof shown in FIGURE 7, wherein it is located in proper alignment with the depending sear lug element 51 so that the sear membear 49 will be rotated counterclockwise, as viewed in FIGURE 7, responsive to pulling the trigger 55 to thereby release the cam 43. The arrangement thus far described is generally similar to that already shown in FIGURE 1 to 6. With this former arrangement there is a possibility that the rear end of the disconnector member may catch on the upper portion of the laterally-projecting lug element 51' at the bottom end of the `depending finger 51 of sear member 49 when the disconnector member is moved rearwardly by the pulling of the trigger 55, which would hold the disconnector member in an elevated position upon return thereof forwardly under the biasing force of the spring 57, which would place the disconnector member in a position wherein it would prevent full return of the lock member 67 -to its normal locked position with the pin element 70 thereof in the lower portion of the vertical slot segment 72. In accordance with the modification of FIGURE 7, a positioning lever 96 is pivoted to the frame at 97, one end of lthe lever underlying t-he normal position of 4the depending lug 69 of lock member 67 and the forward end portion being formed with a depending arm 93 adapted to bear on the disconnector member 53 and being biased thereagainst by a coiled compression spring 99 connected to the frame 14 and acting upwardly on t-he lrear end portion of the lever 96. Thus, the lever 96 is biased in a counterclockwise direction, as viewed in FIGURE 7, toward engagement with the `disconnector member 53', urging the disconnector member 53 to the dotted-view position thereof shown in FIGURE 7. However, the engagement of lug 69 with the lock member 67 in its normal position is sufficient to overcome the force of the biasing spring 99 and `allow the disconnector member 53 to assume the full-line position thereof of FIG- URE 7 wherein the weapon can be fired. If lock member 67 does not return to its proper position, namely, the fullline position thereof shown in FIGURE 7, the disconnector member 53' will assume its dotted view position of FIGURE 7 wherein the disconnector member 53 is not properly aligned with the finger 51, thereby preventing firing of the weapon. The disconnector member is thus placed under the control of lock member 67, preventing firing of the weapon unless the lock member is properly positioned.

With the modification of structure illustrated in FIG- URE 7, after the breech bolt 13 has been returned into engagement with the breech portion 90, -as above-described, the laterally-projecting pin element 70 on the lock member 67 is forced downwardly by the plunger elementy 73 toward thebottom portion of the vertical slot segment 72, thus locking the bolt 13 to the barrel extension, as abovedescribed. As this occurs the lug 69 engages and depresses the rearward portion of the lever 96 against the force of the biasing spring 99, allowing the disconnector member 53 to rotate from the dotted-view position thereof to the full-line position thereof shown in FIGURE 7, which thereby places the disconnector member 53 in proper alignment with the lug 51 of Sear member 49 to enable the weapon to be again red.

This structure, illustrated in FIGURE 7, assures positively that the weapon will not be fired unless the sliding breech block is locked'to the barrel extension.

- It will be noted that the substantially vertical forward end slot segment 72 of the barrel extension 25 constitutes acatch means which is normally engageable by the pin element 70 to hold the breech bolt 13 locked to the barrel 12, the pin element '70 being moved upwardly throughI the vertical slot segment 72 to disengage the lock member Or connector elemfnt 67 from said catch means responsive to the engagement of the cam lug 69 with the tip 79 of the abutment rod 78.

While certain specific embodiments of an improved adjustable lock-up time device for a rearm have been disclosed in the foregoing description, it will be understood that various modications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In a'rearm of the type including a frame, a longitudinally movable barrel, means on the frame for limiting longitudinal barrel movement, a longitudinal breech bolt .aligned with the barrel, means on the frame guiding said breech bolt for sliding movement in the same direction as the barrel, and spring means urging the barrel and breechl bolt forwardly toward forward limiting positions thereof relative to the frame, means interconnecting said breech bolt and barrel, whereby the barrel and breech bolt are movable lrearwardly as a unit, and means disconnecting the breech bolt from the barrel responsive to a predetermined amount of unitary rearward movement of the barrelv .and breech bolt, wherein the rneans interconnecting said breech bolt and barrel comprises at least one rearward extension element on the barrel, a connector element pivoted to the breech bolt, and catch means on the rearward extension element normally lockingly-engage- 8 l able by said connector element, and wherein the means disconnecting the breech bolt from the barrel comprises an abutment element on the frame in the path ofv rearward movement of said yconnector element, Vand whereirrsaid extension `element is formed with alongitudinal slotl and said connector element is provided with a laterally-projecting pin element slidably-engaged in said slot, said catch means comprising a substanti-ally vertical downwardlyextending slot segment at the lforward end ofI said slotin which said pin element normally engages, said pin v'element being elevated through said slot segmentfresponsive to said engagement of the connnector element'with the abutment element.

2. The firearm of claim 1,fand wherein said 'connector element is provided with a depending cam lug which= is substantially longitudinally-aligned with said abutment element in the normal position of said connector elerrlent. 3. The firearm of-claim 2, and wherein vsaid abut-ment element comprises a longitudinal rod element adjustablymounted in the frame in the path of movement of's'a'id cam lug. f* 4. The firearm of claim 3, '.a'nd wherein said lrod element is threadedly-engaged inthe frame: 5. The firearm of claim 4, yandspring means' biasing said -connector element in a direction urging saidpin element toward the bottom end slot segment.

'6. The rear-m of claim 5, and wherein the irearmk includes' a hammer, a scar member controlling lring movement of said hammer, a trigger, a disconnectoi arm pivotally-connecte'd to said trigger, said disconnector arm 'having -a firing position operatively engageable'with'said sear member, means urging said disconnectorarm away from said tiring position, and means on said disconnector arm engageable by said 'cam lug to hold said disconnector Aarm in said firing position when said pin element is substantially in the bottom end of said substantially vertical slot segment.

References Cited y A STATES PATENTS BENJAMIN A. BORCHELT, Primary Examiner.

S. C. BENTLEY, Assistant Examiner.

of said substantially vertical 

